Evaluation of the efficacy of several phytopolymers in terms of their duration of mucoadhesion

In recent years worldwide interest has grown towards the development of mucoadhesive drug delivery systems. These systems are capable of adhering to body's mucosal surfaces for an extended period of time, releasing their drug content in a retarded manner. The use of biopolymers, and in particular phytopolymers, could provide a natural basis for the development of such systems. The aim of this study was to evaluate the rank order of adhesion of several phytopolymers in terms of their invitro duration of mucoadhesion. Several phytopolymers including carrageenan, sodium alginate, tragacanth, locust bean gum, pectin, acacia and guar gum were directly compressed into 100mg flat-faced solid discs with a diameter of 9mm. The duration of mucoadhesion (maximum time interval disc remained in contact with the mucosal surface) of prepared discs to rat intestinal mucosa (model biological membrane), present within a pH 6.8 phosphate buffer at 37 C and under a constant tensile force of 15g, was evaluated. Each study was performed six times and the mean±standard deviation was calculated. Among the polymers investigated, carrageenan (4.6±0.8 h) and guar gum (4.1±0.5 h) containing discs resulted in the longest duration of mucoadhesion, which were significantly (P